Contents Section: Automatic HVAC System All sections

Automatic Air Conditioner: Overview Nissan Altima L31 рестайлинг

Automatic HVAC System 26 illustrations ~681 words

A/C Identification Label

Vehicles with factory installed fluorescent dye have this identification label on the underside of hood.

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Scheme 1: A/C Identification Label

Overview Air Conditioner LAN Control System

The LAN (local area network) system consists of front air control, air mix door motor, intake door motor, and mode door motor.

A configuration of these components is shown in the diagram below.

Scheme 2

Scheme 2: Overview Air Conditioner LAN Control System

OPERATION

The front air control receives data from each of the sensors. It then sends air mix door, mode door and intake door opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor LCU. The air mix door motor, mode door motor and intake door motor read their respective signals according to the address signal. Opening angle indication signals received from the front air control and each of the motor position sensors are compared by the LCUs in each motor with the existing decision and opening angles. Subsequently, HOT/COLD, DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the front air control.

Scheme 3

Scheme 3: OPERATION

Overview of Control system

The control system consists of input sensors, switches, the front air control and outputs.

The relationship of these components is shown in the diagram below

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Scheme 4: Overview of Control system

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Scheme 5: Control Operation

CAN Communication System Description

Refer to " CAN COMMUNICATION ".

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Scheme 6: WORK FLOW

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Scheme 7: SYMPTOM TABLE

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Scheme 8: ENGINE COMPARTMENT

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Scheme 10

Scheme 10: PASSENGER COMPARTMENT

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Scheme 11: Circuit Diagram

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Scheme 12: Wiring Diagram-A/C,A

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Scheme 16: INSPECTION OF FRONT AIR CONTROL
  1. Measure voltage between each terminal and body ground by following "front air control INSPECTION TABLE".

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Scheme 17: FRONT AIR CONTROL HARNESS CONNECTOR TERMINAL LAYOUT

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Scheme 18: FRONT AIR CONTROL INSPECTION TABLE

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Scheme 19

Operational Check

The purpose of the operational check is to confirm that the system operates properly.

System Operation

The front air control receives data from each of the sensors. The front air control sends air mix door, mode door and intake door opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor LCU.

The air mix door motor, mode door motor and intake door motor read their respective signals according to the address signal. Opening angle indication signals received from the front air control and each of the motor position sensors are compared by the LCU's in each motor with the existing decision and opening angles. Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the front air control.

Scheme 20

Scheme 20: System Operation

Scheme 21

Scheme 21: Mode Door Control Specification

The front air control receives data from each of the sensors. The amplifier sends air mix door, mode door and intake door motor opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor LCU.

The air mix door motor, mode door motor and intake door motor read their respective signals according to the address signal. Opening angle indication signals received from the front air control and each of the motor position sensors are compared by the LCUs in each motor with the existing decision and opening angles. Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the front air control.

Scheme 22

Scheme 22: System Operation

Scheme 23

Scheme 23: Air Mix Door Control Specification

The intake door control determines intake door position based on the ambient temperature, the intake air temperature and the in-vehicle temperature. When the front air control is set to DEFROST, or OFF, the front air control sets the intake door at the fresh position.

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Scheme 24: System Operation

Scheme 25

Scheme 25: Intake Door Control Specification

SYSTEM DESCRIPTION

Front air control controls compressor operation by ambient temperature and signal from ECM.

COMPONENT DESCRIPTION

The sunload sensor is located on the right defroster grille. It detects sunload entering through windshield by means of a photo diode. The sensor converts the sunload into a current value which is then input into the front air control.

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Scheme 26: COMPONENT DESCRIPTION

BREAK-IN OPERATION

When replacing compressor clutch assembly, always conduct the break-in operation. This is done by engaging and disengaging the clutch about 30 times. Break-in operation raises the level of transmitted torque.